Rename the tuples selection list example to mention tuples

Making this one look like it was *the* canonical example wasn't a good idea.

docs/examples/widgets/selection_list_tuples.py

@@ -0,0 +1,28 @@
+from textual.app import App, ComposeResult
+from textual.widgets import Footer, Header, SelectionList
+
+
+class SelectionListApp(App[None]):
+    CSS_PATH = "selection_list.css"
+
+    def compose(self) -> ComposeResult:
+        yield Header()
+        yield SelectionList[int](
+            ("Falken's Maze", 0, True),
+            ("Black Jack", 1),
+            ("Gin Rummy", 2),
+            ("Hearts", 3),
+            ("Bridge", 4),
+            ("Checkers", 5),
+            ("Chess", 6, True),
+            ("Poker", 7),
+            ("Fighter Combat", 8, True),
+        )
+        yield Footer()
+
+    def on_mount(self) -> None:
+        self.query_one(SelectionList).border_title = "Shall we play some games?"
+
+
+if __name__ == "__main__":
+    SelectionListApp().run()